Cataract Surgery and the Risk of Conversion from Dry to Neovascular Age-Related Macular Degeneration in the IRIS®...

To evaluate the association between cataract surgery (CS) and the risk of conversion from dry age-related macular degeneration (dAMD) to neovascular AMD (nvAMD) and to identify factors associated with conversion.

Population-based retrospective time-to-event study.

Eyes of patients 55 years of age or older with early or intermediate dAMD and phakic status at baseline were identified in the American Academy of Ophthalmology IRIS® Registry (Intelligent Research in Sight) on or after January 1, 2016, through December 31, 2022. Eyes that underwent CS were classified as exposed; those without CS during the study period were classified as nonexposed.

Propensity score matching was used to match eyes 1:1 on age, sex, race and ethnicity, laterality, AMD stage, and smoking status. Cataract surgery was modeled as a time-varying exposure. We used Cox proportional hazards regression to estimate the hazard of conversion to nvAMD.

Conversion from dAMD to nvAMD, defined by registry-derived diagnosis codes, between exposed and nonexposed cohorts.

After matching, 40 053 eyes were included in each exposed and nonexposed cohort (n = 80 106 eyes total). Cataract surgery was associated with a higher risk of nvAMD conversion (hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.16-1.30; P < 0.001). Time-varying analysis demonstrated that this association was strongest early in follow-up (HR, approximately 2.5 in year 1) and declined steadily, reaching nonsignificance (HR, approximately 1.0) by year 4. At year 6, the cumulative incidence of nvAMD was 17.7% in the exposed cohort vs 15.2% in the nonexposed cohort. Baseline AMD stage moderated the effect of CS, with weaker effects of CS for intermediate AMD (interaction HR, 0.82; 95% CI, 0.73-0.92).

Cataract surgery was associated with a modestly increased overall rate of conversion from dAMD to nvAMD; however, the time-dependent pattern suggests that the observed association likely reflects increased surveillance or unrecognized preexisting nvAMD, rather than a sustained biological effect of surgery. The absolute risk difference was small (approximately 3.3% over 6 years). These findings support careful perioperative evaluation in patients with dAMD, but do not implicate CS as a long-term driver of neovascular conversion.

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